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Updated: Jun 14, 2026
Chromosome Preparation From Cultured Cells
Published on: January 28, 2014
Philadelphia chromosome-positive acute lymphoblastic leukemia: a cytogenetic study of 33 patients diagnosed between
Etienne De Braekeleer1, Nathalie Douet-Guilbert, Frédéric Morel
1Université de Brest, Brest, France.
Background:
The Philadelphia (Ph) chromosome, resulting from a t(9;22)(q34;q11), is one of the most frequent chromosomal abnormalities observed among patients with acute lymphoblastic leukemia (ALL). Main of study: To analyze the distribution of Ph chromosome-positive ALL patients.
Patients And Methods:
Conventional cytogenetic analysis was performed on bone marrow cells at the time of diagnosis and/or relapse of 208 patients shown to have B-cell ALL. Fluorescent in situ hybridization studies using probe LSI BCR-ABL dual ES color (Abbott, Rungis, France) and other types of probes were performed on the available cytogenetic pellets.
Results:
Thirty-three Ph chromosome-positive ALL patients were identified between 1981 and 2008. The Ph chromosome was present in 39.7% of the patients older than 25 years, but in only 4.3% of the patients younger than 15 years. A pseudodiploid karyotype was found in 68.75% of the patients and hypodiploidy in a further 15.6% of the patients. FISH studies revealed the breakpoint to be located in the major breakpoint cluster region in 20% of the patients and in the minor in the remaining 80% of the patients. Complex rearrangements of the derivative chromosomes 9 or 22 were identified in four patients, including a complex Ph translocation, t(9;22;X).
Conclusion:
Ph chromosome-positive ALL patients show cytogenetic characteristics that differ from those of other ALL patients.
